RITE-TORISHIMA LABORATORY
in OSAKA GAS Co., LTD.

(1) Objectives

Adsorption recovery systems（Canisters）of volatile hydrocarbons were developed, which prevent emission of gasoline vapors from the gasoline tanks of motor vehicles to the air during filling it at gas stations and parking.

The target of the development was that the size of the canisters was half of the current ones and recovery rate of gasoline vapor was over 95 %.

(2) Contents of the Developments

The development of the canisters was done as follows by using our proprietary high performance activated carbon fibers(ACF) which adsorb large amount of gasoline vapor per weight;

a Developments of technologies of processing of ACF to high density sheets, which enabled to adsorb large amount of gasoline vapor per volume. b Developments of canisters which were compact , low pressure drop and high recovery rate.

(3) Results

Results of the developments were as follows;

a Developments of high density sheets

Preform technologies were developed ,resulting in that amount of binders could be decreased to about 2% ,and that amount of powdered activated carbons which lower the cost of ACF sheets could be increased as much as 77% of the sheet weight. ACF high density sheets of as large as 300mm×200mm were obtained by using the preform technologies.

Automatically processing system was developed ,which enabled high speed of sheet processing.

b Developments of canisters

Canisters whose ACF sheet packing density was up to 0.4g/cm³ were developed. Effective adsorption amount of gasoline vapor of the canisters (measured by JASO method ) whose pressure drop was the same as that of the current ones was 1.6 times as much as the current ones. The recovery rate of the canisters could be over 95%(measured by JASO method ) ,when their assembled ACF sheet volume was over 550 cm³.

c Applied Patent

Title Canister , Filed 3. 28. 1994, Applied No 6-8228